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It was around mid 70s here today and the car temp was right around 220 all day and as high as 230. When i checked the temp in the DIC , the trans,oil, and the coolant were around 220.When i got on the freeway the temp dropped to one step below 220 so i guess that would be 200 and in the DIC the trans and oil temp were still around 220 but the coolant was around high 170s.
My car is a 2004 A4 with around 18k miles, should i be worried about this or is this normal, its like this on most hot days.
The thermostat controls the temp of the engine. If the cooling system is in good shape and operating correctly, it'll run very close to the same temp on a 70 degree day as it does on a 90 degree day. These cars are designed to run in the temps you described so I'd be sure the front of the radiator was clean, and the anti-freeze is full, and not worry about it.
I had the same questions on mine earlier this year, your temps are normal, this info below was garnered from another post but pretty much sums it up. If it gets hot in traffic, turn "ON" the air, it turns on the fan
***The low speed cooling fan is on when the coolant temperature reaches 226°F. It is turned off if the coolant temperature lowers to 219°F.
The high speed cooling fan is on when the coolant temperature reaches 235°F. It is turned off if the coolant temperature lowers to 226°F. When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
I had the same problem about a month ago and when changing the oil at home with ramps I noticded a piece of a plastic bag up in the radiator area. It was not visble unless you are on your back and looking directly up in that area. When I pulled bag ,out came some straw, grass, leaves, cigarette butts, so I went and got small tip air nozzel and blew up in there and still more debris, dirt, dust, came out. I was amazed. I made an extension for the air hose with a small long rubber hose added to the tip of the air nozzel so I could blow further up in the area and still more trash etc came out. By the way if you do this make sure you have on eye protection such as safety glasses and you will definitely need a shower afterwards. I plan on always checking this area of the radiator when changing the oil now and even if I dont see anything I am still going to blow that area out as a safe guard. By the way car is running 15 to 20 degrees cooler.
rICHARD
From: Wylie TX --> Less is More, except under the hood !
Also make sure that your black air deflector under the car is not stuck in the wrong angle. You want to make sure it forces air up into the radiator. And as others have said make sure its clean up there in the radiator area. It seems to collect a lot of crap ! I have pulled many objects out of my radiator area.
As Richard stated, the area between the radiator and condenser is small but for some reason is a serious vacuum and stuff some how gets in-between the two. It is not easy to clean them. Be very careful of the fins of the radiator and condenser when cleaning the area.
I recently solved an issue with my Corvette running hot and found 3 issues:
- Radiator inlet had small pieces of black rubber preventing coolant from flowing - replaced radiator - I suspect the rubber pieces were from an old thermostat seal broken apart?
- Plastic tee on small hoses that connect steam vents to top of radiator and surge tank was soft and breaking apart - I replaced it with a stainless tee from eBay
- Jiggle valve orientation on thermostat was at 3:00 - not sure if this matters but I moved it to 12:00
The normal coolant temperature of my car (2008 base model LS3 auto) has always been 198 - 205 F when moving.
It was going as high as 220 F while moving.
Now it's back to 198 - 205.
You can remove the top radiator cover and look down but you won’t see as much compared to laying on the ground looking up.
A water/air wand kit off Amazon will do a nice job cleaning out the fins. Now you’ll need to get the car up about 10” to crawl under the front, but even just reaching up with your hand you’d be surprised how much junk you can wipe off.
New C5 owner here, grateful for this really old info, cuz it’s running @ 230 running back and forth to the parts store that’s just a few miles down the road. I need to flush the system and clean out under the nose.
If you're running around stop and go, depending on ambient temps, 230° is not overheating. IIRC, the high speed fan setting is for 234°? If it's 90° ambient, and you're stop and go with the air on, with stock tuning, stock T-stat, and running the A/C, 230° is probably normal. If it never goes under 230°, that wouldn't be normal. 230° isnt ideal, but it's not overheating, either....
New C5 owner here, grateful for this really old info, cuz it’s running @ 230 running back and forth to the parts store that’s just a few miles down the road. I need to flush the system and clean out under the nose.
Do you have all 3 pieces of the air dam in place?
I suggest you start a new thread.
Last edited by bookyoh; Nov 21, 2025 at 12:10 PM.
Reason: Added text
Car Overheating???
